FRESH evidence has emerged which could help North West solicitor Sally Clark in her appeal against her conviction for the murder of her two children.

Clark, 37, of Wilmslow, Cheshire, was convicted of murder in November, 1999, after a jury heard that the chances of her two baby boys both suffering cot death was 73 million to one.

The statistical argument put forward by Professor Sir Roy Meadow was the key in securing a conviction against Clark.

Despite losing an appeal against her conviction, Clark has continued to protest her innocence in connection with the death of Christopher, who died in December, 1996, aged 11 weeks and Harry, who died on January 26, 1998, aged eight weeks.

Now, experts have called into question Professor Meadow's conclusions after it emerged that both babies died at the peak of lung infection epidemics, a fact unknown at the time of the trial.

Professor Meadow has also revealed that he destroyed the database on which his evidence was based shortly before the trial, meaning that the research could not be scrutinised.

Dr Douglas Fleming, of the Royal College of General Practitioners, studiedreports from GPs nationwide over the five-year period during which the two boys died.

He said: "Both babies died during epidemics. Christopher died just short of a five-year peak. Harry died at a lower peak but still at a time of statistically significant infection.

"There is no way Sally Clark could have known this."

Dr Fleming has questioned why the initial findings of an autopsy on Christopher, which recorded the cause of death as lung infection, were altered after Harry died.

Clark's defence has always insisted that the babies died for reasons unknown to medical science and has suggested that they may both have been victims of cot death. Professor Meadow's use of the key statistical evidence has been criticised by other experts.

Peter Fleming, professor of child health at Bristol University, who wrote the Government report which first introduced the one-in-73m figure, said: "This statistic was never intended as an estimate of real risk. It was never meant to suggest that this was an unnatural occurrence.

"This statistic is of no relevance to a jury trying to under- stand whether babies had died naturally or unnaturally.

"It was used completely out of context and so, without explaining how it was arrived at, it is potentially misleading and dangerous."

Professor Meadow has consistently defended his evidence.

But it has emerged that he shredded confidential research material after he retired from his post at Leeds University, making it unavailable to the defence at the time of the trial.

While she has already lost an appeal to London's Court of Appeal, Clark is understood to be planning to take her case to the European Court of Human Rights.

Clark's father, Frank Lockyer, welcomed the news.

He said: "It is a very interesting development. We are treating it with cautious optimism.

"We are extremely grateful that the gentleman thought to associate this research with our two babies. There are a number of avenues being explored at the moment. We will get there, although it takes a long time."

Mr Lockyer had not yet spoken to Clark about the news.

He added: "Sally is bearing up. She has been through a difficult time lately with her third Christmas in prison separated from her young baby, whom she sees only once a month.